The objective of this study is to assess the safety and efficacy of the buprenorphine transdermal system (5, 10, and 20 mg) in comparison to placebo transdermal system and hydrocodone/acetaminophen in subjects with chronic back pain. The double-blind treatment intervention duration is 56 days during which time supplemental analgesic medication (ibuprofen) will be provided to all subjects in addition to study drug.